1. Field of the Invention
The invention relates to a current sensor, and more particularly to a current sensor for measuring the inhomogeneity of potential distribution of gapless metal oxide arresters.
2. Description of the Related Art
To ensure the safe operation of metal oxide arresters, before mass production, studies on the whole potential distribution is a must. If the inhomogeneous coefficient of potential distribution of the arresters is bigger than a set standard, the local electric load rate of resistors will be too high, which may result in thermal breakdown of the resistors and safety accidents of power systems. Nowadays, a commonly-used method of measuring potential distribution is fiber-current methods.
For conventional equipment of measuring potential distribution, the sensing head is generally a passive device. Current intensity measured by the sensing head is often modulated into light intensity signals or frequency signals and sent to a signal processing unit at a low voltage side by fibers. However, the acquired current signals have bad real time, and relevant information such as current waveform, effective value, peak value, and frequency is not available, so the potential distribution of metal oxide arresters can not be measured more accurately.